Inked ribbon for typewriters and other business machines



July 19, 1966 R. J. SPERRY ETAL 3,

INKED RIBBON FOR TYPEWRITERS AND OTHER BUSINESS MACHINES Filed Aug. 17, 1965 HA r! 14! Robert Jii'per'a' .B. Vwidet koofii n LEW United States Patent 0 3,261,446 INKED RIBBON FOR TYIEWRITERS AND OTHER BUSINESS MACHINES Robert J. Sperry, Box 224, Manomet, Mass, and Nelson This application is a continuation-impart of our copending application Serial No. 238,489, filed November 19. 1962, entitled Improved Inked Ribbon for Typewriters and Other Business Machines, now Patent No. 3,205,998.

This invention relates to an improved inked ribbon and to a method and apparatus for producing an inked ribbon in which a required quantity of ink is combined with a protective coating overlying one side of the ribbon against which the type face of a typewriter machine may be pressed to provide desired impressions on paper or other writing surface.

It is a chief object of the invention, therefore, to provide a novel typewriter ribbon having a protective coating or backing applied at one side thereof in order to avoid excess ink being collected on the type faces of a typewriter machine.

A further object of the invention is to devise a method and apparatus for combining an inking material with a plastic coating in a typewriter ribbon fabric in a novel manner whereby a relatively large quantity of ink may be introduced into the typewriter ribbon to provide for relatively long operating life. Still a further object is to devise a method of impregnating a special type of inking material in a ribbon coating which is capable of absorb- I ing portions of ink and slowly releasing the ink during the use of the ribbon with the result that a very desirable ink recovery characteristic is realized in the ribbon performance.

These and other objects and novel features of the invention will be set forth in the following description and illustrated in the accompanying drawings, in which:

FIGURE 1 is a fragmentary cross sectional view of a ribbon fabric having a protective coating applied thereon;

FIGURE 2 is a side elevational view indicating in diagrammatic form the method of inking of the invention;

FIGURE 3 is an enlarged fragmentary cross sectional view of an inked ribbon material of the invention; and

FIGURE 4 is another cross sectional view of a fabric yarn component impregnated with ink in accordance with the invention. 1

With the foregoing objectives in mind. we have devised a novel typewriter ribbon body which is based on r the concept of introducing both a greasy type ink and a non-greasy type protective coating material into the ribbon whereby there may be realized a combination of the greasy ink material with the ribbon fabric after it has been impregnated with the protective coating material.

The use of two dissimilar materials in this way is based on the idea of providing a special type of ink which is capable of penetrating the coating material. The protective coating is introduced into the fabric in a manner such that exposed yarn surfaces at one side of the ribbon body are relatively heavily impregnated to provide a reinforced type-receiving surface while yarn portion at the other side of the ribbon are only very lightly impregnated so that these yarn portions are, in effect, covered with thin films of the protective coating material.

Ink prepared in accordance with the invention is caused to penetrate the film and become absorbed in the yarn fabrics to provide an ink reservoir. The absorbed ink thus occurring as a reservoir is then retentively held by the thin films of the protective coating on the yarns in a manner such that a slow release of ink is realized as the ribbon is used and a longer and more effective ribbon life is obtained.

It should be understood that manufacture of conventional inked ribbons has been based on the theory of inking a very absorbent fabric and causing ink to penetrate as rapidly as possible. In contrast the invention method proceeds on a different basis of using an already partially impregnated fabric which will accept ink less freely.

The technique of combinnig ink with a fabric in which impregnation is controlled in part by a suitable coating compound first applied to the fabric, is indicated diagrammatically by the section of ribbon fabric R in FIGURE 1 and in a somewhat more detailed form by the impregnated yarns Y1 and Y2 of FIGURES 3 and 4.

Considering in detail one desirable method of producing the typewriter ribbon of the invention, We start with a fabric of well-known type such as one made from twisted cotton yarns Y1 and Y2 of long stable character. This fabric is coated with a special coating material which is applied at one side of the fabric with heat and pressure to provide an impregnated body as diagrammatically suggested in FIGURE 3. The coating material which is thus impregnated in the fabric comprises a urethane compound such as, for example, a polyurethane consisting of the reaction product obtained by reacting a polyisocyanate and a polyhydroxy compound as follows:

OCN--R'NCC+NOR'-OH R-N H-COO--R'-OCO-N I-l n In utilizing as an ink reservoir a fabric impregnated with a polyurethane of the type noted, a woven fabric of.

the polyurethane under heat and pressure, it undergoes an appreciable decrease in its thickness dimension. In so doing the fabric becomes potentially capable of absorbing and containing a quantity of ink of a specific type. When ink of a suitable greasy nature is applied to the coated ribbon there is induced an increase in thickness of the fabric somewhat in the nature of an absorption or swelling action by which the fabric substantially regains its normal thickness. In this way a relatively large amount of ink is absorbed and there is realized a desirable reservoir of ink which can be held in a desirable manner in the coated fabric.

Referring more in detail to FIGURE 1. a ribbon fabric R of the preferred 270 count indicated, is shown coated and partly impregnated with the polyurethane compound. In this fabric R the protective coating material of polyurethane is represented diagrammatically by dark stippled areas to indicate a relatively heavy impregnation of the coating material at the type-receiving surface 2. Immediately below this surface 2 the stippled areas are shown becoming progressively lighter through to the opposite side of the ribbon fabric to denote progressively lesser amounts of the polyurethane being present on the yarns reaching through to the opposite surface 4. Application of the coating material in this manner may be controlled by means of well-known press roll apparatus for forcing coating material into a fabric. In FIGURES 3 and 4 lightly stippled areas W have 'been indicated diagrammatically on strands Y1.

The protectively coated fabric R may be conveniently supplied from a spool S as suggested at the left hand side of FIGURE 2. The spool may be mounted on a suitable frame and supported in front of the spool S. In a raised position are inking rolls 8 and 10 which are arranged in rolling contact to provide a nip area. In this nip area is located an ink mass M periodically furnished by an operator in some desirable manner. The ink mass is characterized by an ability to penetrate the film of protective coating material at the lightly impregnated side of the ribbon. As illustrative of an ink of this nature, we provide an ink consisting of a greasy mineral oil type carbon black mass which contains fatty acid. The ribbon fabric R is carried around guide rolls 12 and 14 and then into the ink mass M and through the nip of the rolls.

By means of the procedure described there is caused to occur a substantial penetration of the urethane compound into the yarns and by thereafter applying an ink of the character described, it is found that a relatively large quantity of ink may be absorbed in the fabric and held in such a manner that it constitutes a novel reservoir. For example, in one typical ink-applying operation a ribbon of standard typewriter width, and the 270 count noted, and having a length of 300 yards, was impregnated with a quantity of ink of approximately 75 grams by weight. This quantity of ink gave unusual operating performance as hereinafter described in detail.

It is also pointed out that the technique of combining the ink with the coated ribbon fabric is accomplished in such a way that almost all of the ink introduced into the ribbon-is absorbed and contained in a manner so that the inked side of the ribbon may be wound around the coated side without appreciable transfer or offsetting of ink onto the coating during subsequent use.

This, it will be understood, is an important feature of the invention with reference especially to handling of :he operator and a much cleaner handling is therefore realized.

The combined effect of a relatively large quantity of nk being absorbed in the ribbon while retaining the alastic type of protective coating at one side comprised )y the polyurethane, provides for unusually long wearing ife, as well as desirable performance on the typewriter. [t is found that the plastic coating tends to maintain he type faces of a typewriter in a relatively clean conlition by resisting any accumulation of ink or lint and bus largely eliminates need for cleaning of type faces.

The ribbon of the invention may be used in connection vith all varieties of business machines which print by lirect imprint of type through an inked ribbon, such as :ash registers, addressographs, multigraphs, adding ma- :hines and many other statistical machines, including the nodern printing computers used in connection with iunched cards.

In a typical installation of the ribbon of the invention in an office typewriter operating daily for a period of even hours each day, it was found that an unusual inirease in performance life was obtained in comparison vith conventional ribbons. For example, in the installaion referred to above, it was observed that a satisfactory vorking period of a conventional ribbon was from one 0 two weeks, whereas in comparison the invention ribbon it the end of a similar period continued to be in exellent condition. In this instance an increase in satisactory performance life of the invention ribbon was ound to be extended over a period of from three to our weeks, approximately double conventional ribbon life, hus indicating an increase in efficiency of approximately 00%.

An outstanding characteristic exhibited by the invenion ribbon in use was its recovery life. It should be lI1ClISIOOd that conventional ribbons have a well recog- 4 nized recovery characteristic whereby when a ribbon is allowed to stand for a certain period of time it will regain its inking strength for a limited period and then lose it.

In the case of the invention ribbon, the recovery life has been observed to be materially improved and a sharper and more clearly defined print produced from the beginning to the end of the useful life of the ribbon.

As an example of another type of test of the invention ribbon, an automatic electric typewriter was equipped with the ribbon and this machine was set at a controlled striking pressure and was further operated to produce five hundred typewritten sheets, each sheet having forty lines of letters. The same operation was carried out with a comparable cotton fiber ribbon having conventional ink impregnation. Here it was found that approximately only two hundred fifty typewritten sheets having forty lines of letters could be produced satisfactorily with this conventional ink impregnation. Various other similar tests were also observed.

While we have illustrated preferred embodiments of the invention, it should be understood that modifications and changes may be resorted to within the scope of the appended claims.

We claim:

E. An improved typewriter ribbon comprising a length of ribbon fabric having a protective coating of a urethane compound appiled at one side of the ribbon to provide a reinforced type receiving surface, portions of the coating material at the said type receiving surface being relatively heavily impregnated therein, other portions of the coating material being relatively lightly impregnated through the ribbon fabric to the opposite side thereof to overlie constituent fabric yarns in the form of thin outer films, a typewriter ribbon ink applied to the ribbon fabric yarns over the said thin outer films of protective coating material to provide an inking surface, said ink consisting of a greasy mineral oil and carbon black mass in which is contained a fatty acid, said fabric yarns having absorbed therein in varying degree quantitie of said ink which have permeated through the said thin outer urethane films into the fabric yarns to provide a reservoir of ink, said reservoir of ink being retentively held by said films of coating material whereby a slow release of ink from the yarns is accomplished when the ribbon fabric is pressed against a writing surface by a type face.

2. An improved typewriter ribbon comprising a length of ribbon fabric having a protective coating of a polyurethane consisting of the reaction product obtained by reacting a polyisocyanate and a polyhydroxy compound, said coating being applied at one side of the ribbon to provide a reinforced type receiving surface, portions of the coating material at the said type receiving surface being relatively heavily impregnated therein, other portions of the coating material being relatively lightly imprcgnaled through the ribbon fabric to the opposite side thereof to overlie constituent fabric yarns in the form of thin outer films, a typewriter ribbon ink applied to the ribbon fabric yarns over the said thin outer films of protective coating material to provide an inking surface, said ink consisting of a greasy mineral oil and carbon black mass in which is contained a fatty acid, said fabric yarns having absorbed therein in varying degree quantities of said ink which have permeated through the said thin outer polyurethane films into the fabric yarns to provide a reservoir of ink, said reservoir of ink being retentively held by said films of coating material whereby a slow release of ink from the yarns is accomplished when the ribbon fabric is pressed against a writing surface by a type face.

3. A method of producing a typewriter ribbon which comprises providing a length of typewriter ribbon fabric having a predetermined count and thickness. applying to one side of the length of ribbon fabric a coating of a polyurethane compound with heat and pressure to impregnate portions of the fabric with the polyurethane and to simultaneously reduce the thickness of the fabric, then applying a greasy ink to the uncoated side of the length of fabric and absorbing portions of the greasy ink in the urethane coated fabric to provide for the ribbon fabric substantially regaining its normal thickness whereby a reservoir of ink is produced in the fabric.

4. A method according to claim 3 in which the urethane compound is a polyurethane consisting of a reaction product obtained by reacting a polyisocyanate and a polyhydroxy compound.

5. A method according to claim 4 in which the fabric is made of twitsed cotton fibers and has a count of from about 250 to about 300.

6. A method according to claim 1 in which the fabric is made of silk fibers.

References Cited by the Examiner UNITED STATES PATENTS 420,312 1/1890 Rogers l97172 1,364,788 1/1921 Neidich 197-172 X 1,700,415 1/1929 Neitlich 97l72 X 1,732,187 10/1929 lclton 197 172 2,475,336 7/1949 Pctz m. 197l72 X 2,657,157 10/1953 Francis l97---172 X 3,080,954 3/1963 Newman et a1. 197-472 DAVID KLEIN, Primary Examiner. 

1. AN IMPROVED TYPEWRITER RIBBON COMPRISING A LENGTH OF RIBBON FABRIC HAVING A PROTECTIVE COATING OF A URETHANE COMPOUND APPLIED AT ONE SIDE OF THE RIBBON TO PROVIDE A REINFORCED TYPE RECEIVING SURFACE, PORTIONS OF THE COATING MATERIAL AT THE SAID TYPE RECEIVING SURFACE BEING RELATIVELY HEAVILY IMPREGNATED THEREIN, OTHER PORTIONS OF THE COATING MATERIAL BEING RELATIVELY LIGHTLY IMPREGNATED THROUGH THR RIBBON FABRIC TO THE OPPOSITE SIDE THEREOF TO OVERLIE CONSTITUENT FABRIC YARNS IN THE FORM OF THIN OUTER FILMS A TYPEWRITER RIBBON INK APPLIED TO THE RIBBON FABRIC YARNS OVER THE SAID THIN OUTER FILMS OF PROTECTIVE COATING MATERIAL TO PROVIDE AN INKING SURFACE, SAID INK CONSISTING OF A GREASY MINERAL OIL AND CARBON BLACK MASS IN WHICH IS CONTAINED A FATTY ACID, SAID FABRIC YARNS HAVING ABSORBED THEREIN IN VARYING DEGREE QUANTITIES OF SAID INK WHICH HAVE PERMEATED THROUGH THE SAID THIN OUTER URETHANE FILMS INTO THE FABRIC YARNS TO PROVIDE A RESERVOIR OF INK, SAID RESERVOIR OF INK BEING RETENTIVELY HELD BY SAID FILMS OF COATING MATERIAL WHEREBY A SLOW RELEASE OF INK FROM THE YARNS IS ACCOMPLISHED WHEN THE RIBBON FABRIC IS PRESSED AGAINST A WRITING SURFACE BY A TYPE FACE. 